1. Field of the Invention
This invention relates to floor jacks and particularly to floor jacks having a pivot point located before the anchor mechanism.
2. Description of the Related Art
One of the most common problems in laying an outdoor deck or wood floor is that the wooden boards tend to warp. Due to the nature of woodcutting, wood boards often warp in the horizontal plane, forming a flat, curved board. The construction of wood floors and decks is generally based on laying straight runs of boards forming a square or rectangular structure, curved boards present a problem. A simple but inefficient solution is to restrict the usable materials to only straight boards. A more practical solution is to use a means to straighten out the deck boards as they are installed. By anchoring one side of a board in its proper position, it is possible to bend a board back into a straight position, where it can be fastened to the underlying framing to secure it in place. Several devices have been developed over the years to accomplish this task. For example U.S. Pat. No. 14,676 shows a device that clamps to a joist. A long arm extends forward, which is used to contact a given board. A handle extends upward and is pivotable to cause the arm to move forward, pushing against a board, as the handle is depressed. In this way, the board can be straightened. Similar devices are found in U.S. Pat. Nos. 81,803, 299,220, 302,416, 375,147, 376,439, 460,790, 764,128, 797,245, 975,566, 1,231,461, 1,354,854, 2,589,404, 2,780,437, 3,524,623, 3,779,515,4,620,691, 5,248,127, D 353,987, 5,527,014.
All of the above devices use some type of lever action to straighten boards and they all use some type of means to secure the device in place to prevent it from moving. All of them suffer from some problem that makes their use impractical.
There are three main problems with these devices. First, is the type of fastening used to hold the device in place; second, is the leverage system used; and third, is the placement of the pivot point to obtain the leverage. Regarding the type of fastening, there are two main types: clamps and spikes. Clamps are generally placed around joists that lie beneath the floor or deck surface. The clamps are labor intensive to install. Moreover, where access to the joists is limited or restricted, the clamps are useless. Spikes are simpler to install and remove. However, some of the device require such a great deal of holding power (due to their poor leverage as discussed below), they require an excessive number of spikes. Such large number of spikes makes removal of the tool difficult and can do serious damage to the joists. The second problem is the leverage system used. In some of these devices, the devices are long and flat. It appears that some of them can be two feet or more in length. This is a problem when working in tight spaces. Such long machines cannot be used near walls and other obstructions. Finally, most of these devices use a pivot point for the handle that is in front of the fastening mechanism. What this means is that as the handle is activated, it applies a moment force on the tool that pushes the jack portion forward, while simultaneously trying to lift the fastened end up. It is because of this lifting tendency that large clamps and multiple spikes are required for the devices to work at all. In many cases, unless the devices are sufficiently held down, the device merely rotates upward from the back, using the bent board as a fulcrum, instead of operating the other way around.